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cross-sections, for the purpose of showing the inclination, thickness, and sequence of the rock sheets. Much time has also been devoted to the tracing of the boundaries and areal distribution of these different strata upon the surface, and also to office work in mapping and recording the results thus determined.

I have made several trips for the purpose of ascertaining the boundaries of my district and locating my assistants upon them. In addition to these, many visits have been made by me to the rocks in the vicinity of Austin for the purpose of ascertaining their sequence and defining their characteristics.

Three accurate parallel cross-sections of the region have been commenced and progressed towards completion. These approximately follow the breaks of the Red, the Brazos, and the Colorado rivers, respectively, and are further explained in the report of the work of Mr. Taff, which is appended. These cross-sections have been made with great care and accuracy, and when completed will be of incalculable value in all stratigraphic and common determinations.

The tracing of the areal extent of the formations determined by the crosssections has been faithfully performed by Messrs. J. A. Taff, C. C. McCulloch, N. F. Drake, and J. S. Stone, as will be seen in their appended reports. Over 2204 miles of partings (boundaries) have been traced and located, fixing permanently the lines of demarcation between the different characters of the country composing the surface of the region. These boundaries are absolutely essential to all geologic questions that can arise concerning the region and are a fundamental and essential portion of the work. The main subdivisions of the district have been accurately located, including the Upper and Lower Cross Timbers, the Grand Prairie, the Black Prairie, and the boundary between the Cretaceous region and the East Texas region on the east, and the Central Texas features on the west.

The foregoing operations have all been essential and preliminary to a thorough economic investigation of the region. All lines of economic work, however, have progressed hand in hand with these preliminary surveys, as fast as possible, and already results of value are foreshadowed and are being described and recorded as rapidly as accuracy will permit.